HOUSTON COUNTY. 



323 



ANALYSES OF GRAY SANDY SOILS 



(upland). 









Wood County. 

 Soil. 



Smith County. 

 Soil. 



Subsoil. 



Insoluble silica 



Soluble silica : 



93.051 

 3.364 

 0.114 

 0.074 

 0.031 

 0.061 

 0.111 

 0.611 

 0.908 

 0.169 

 0.012 

 0.611 



94.350 

 0.525 

 0.111 

 0.105 

 0.076 

 0.061 

 0.040 

 2.050 

 0.303 

 0.237 

 0.031 

 2.035 



93.458 

 1.820 



Potash 



0.148 



Soda 



0.080 



Lime 



0.090 



Magnesia 



0.031 



Brown oxide manganese 



0.121 





2.337 



Alumina 



0.779 



Phosphoric acid 



0.295 



Sulphuric acid 



0.105 



Water and organic 



0.911 





99.117 



99.926 



100.175 



Taking Professor E. W. Hilgard's determinations as to the amounts of 

 potash, phosphoric acid, and lime which are necessary to secure fertility and 

 lasting qualities to a soil, we find that in these soils (second table of analyses) 

 the percentage of potash is quite low, being barely above the lowest limit 

 needed in fertile soils. The lime, which if present in sufficient quantity 

 would in some measure make up for the deficiency in potash, is present in 

 such small amounts as to be insufficient to even render available for plant 

 food the phosphoric acid which exists in the soil. 



This ingredient (phosphoric acid) is, however, in rather larger quantity 

 than usual, and to its presence and amount is largely due the fertility and 

 durability that the soils do possess. 



But these are not the only soils which do not contain these essential in- 

 gredients in such quantities as will secure the durability so desired. This 

 will be readily seen by an examination of the red sandy and clayey soils. 

 This soil, which was taken as characteristic of this class by Dr. Loughridge, 

 is described by him as "a dark loamy soil near Palestine, Anderson County, 

 subsoil eight to twelve inches."* (First table of analyses.) 



Both the soil and subsoil are deficient in the amounts of potash they con- 

 tain, although they have fair percentages of phosphoric acid and lime. Not 

 sufficient, however, to make up for the small amount of potash. 



The mulatto soils are more nearly the ideal in composition, although they 

 vary considerably, as will be seen by the analyses given below, which were 

 made at the Survey labratory at the Agricultural and Mechanical College by 

 Mr. P. S. Tilson. 



*Page 25 Cotton Production U. S. 



[Note. — Heading of analyses of page 322 should 



"Ked sandy and clayey."] 



28— geol. 



